VW caught for designing cars to emit less pollution when being tested

Discussion in 'Architecture & Engineering' started by scifes, Sep 22, 2015.

  1. scifes In withdrawal. Valued Senior Member

    I find it super interesting and would like to discuss it. here's a piece about it:

    Why would they do that? what would happen if their cars ran in clean mode the whole time? like what part of the engine would be less efficient?

    and how the HELL can a company that big have a meeting, discussion, then assign software engineers to write this into the car's software? and obviously send people to research the testing procedure and conditions, i mean that looks as much work as just freaking fixing the emissions problem to begin with! and they did their software trick so good only now they've been discovered, after the cars been out for years.

    and 40 times what's allowed?? that sounds crazy, i'm really interested in the process that generates NOx and how that affects car performance.

    P.S: yeah I'm back, hopefully not in full capacity, this place sucks time like... facebook or something, which I deactivate 84%of the time.
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  3. billvon Valued Senior Member

    I suspect this decision was never explicitly made. The process may have gone something like this:

    CEO: Make SURE our cars pass emissions tests.
    Engineer 1:Well, boss, I can make it pass the test by changing ignition advance to X, and increasing mixture, but that's going to affect . . . .
    Engineering manager:I don't care about the details! The CEO is breathing down my neck, and we HAVE to make this work! Do whatever you have to.

    CEO: Our cars seem to have less power and lower gas mileage per Consumers Reports. Fix it!
    Engineer 1:Look, I told you, making those changes to pass the test has some other effects.
    Engineer 2:Well, I can solve the problem by making a special performance mode that only kicks in when the guy floors it! It will also help with gas mileage.
    Engineering manager: Excellent! Do it.

    CEO: I heard we have a new performance mode. Why don't we use that all the time? Why the heck would you ever put the car in LOW performance mode?
    Engineering manager: Uh - not sure. The new engineer came up with that solution. But I can have him do it all the time. Hey new engineer! Turn that on all the time.
    Engineer 2: Well, remember, then it won't pass emissions.
    Engineering manager: OK, then enable it almost all the time.
    scifes and Walter L. Wagner like this.
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  5. Walter L. Wagner Cosmic Truth Seeker Valued Senior Member


    I'm a bit more cynical, I suppose. It probably went more like. Management: 'Let's see if we can design something that will both pass the emissions tests, and get good mileage,let's do it.' Engineer: I can design it, but if we get caught, we might be in trouble. It requires designing something that gives different readings during the testing compared to open road.' Manager; 'Dont' bother me with the details, just do it.' Or something like that.
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  7. rpenner Fully Wired Valued Senior Member

    From the bottom of the large paragraph of page 4 of the Notice of Violation:
    (emphasis added)

    Here the problem is that it's not evasion of a prescribed testing regime but violation of emission control law.

    42 USC § 7522 (a)(1) and 42 USC § 7522(a)(3)(B) provide:
    So doomed are they.

    Last edited: Sep 22, 2015
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  8. billvon Valued Senior Member

    As always, Hanlon's Razor applies; incompetence is always more likely than malice.
  9. rpenner Fully Wired Valued Senior Member

    The bolded claim of admission sounds a lot like evidence of malice, however.
  10. Capracus Valued Senior Member

    VW did at the corporate level what performance enthusiasts do individually. They deliberately altered prescribed engine management programming to gain an increase in performance.

    Programming parameters are set by the manufacturer to balance performance, economy, and emissions. This effect doesn’t sit well with many drivers, some of whom are willing to bend the rules a bit. This is where aftermarket programmers come into the picture. Some of the benefits of these products include the following:
    • More power.
    • Better acceleration.
    • Finer control over the vehicle at high speeds.
    Sometimes these programs target transmission problems, and some claim that these products can cure problems like rough shifting and loud noises. Others say that reprogramming can extend the life of the transmission. A handful even say that today’s gearboxes are designed to fall apart much sooner than necessary, and that altering the software simply allows the buyer to enjoy the quality and reliability he or she deserves from a new vehicle.

    Despite these claims, we recommend that you tread very carefully when installing non-manufacturer software. Not only might you make the vehicle unsafe to drive, you may also run afoul of the Environmental Protection Agency (EPA) or other federal regulators.


    VW went a step further than the individual by incorporating additional programming to conceal it from emissions testing.

    VW’s defeat devices were subtler and more insidious. Instead of just turning off and on with the air conditioner, they took into account “the position of the steering wheel, vehicle speed, the duration of the engine’s operation, and barometric pressure”—a list of criteria that precisely mirrors the conditions of the EPA’s required emissions testing.

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  11. Daecon Kiwi fruit Valued Senior Member

    Hanlon obviously never met people.
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  12. scifes In withdrawal. Valued Senior Member

    Never heard of a razor other than occam's, will look it up.
    Thanks for simulating what the decision process that lead to this might've been like, valuable insight. The links to the EPA's documents, would want to read those too.

    But what about the engine's chemistry, I know a bit about internal combustion engines, is the tradeoff as simple as more complete combustion=more energy output & NOx?
  13. billvon Valued Senior Member

    Unfortunately, no.
    If you lean the mixture, you get more complete combustion. Less particulates and unburned HC - yay! But temperatures go up, and thus NOx emissions go up.
    Retarding ignition can reduce HC emissions (yay), but that reduces peak power and reduces fuel economy.
    Increasing compression can get some power and fuel economy back - but then you need higher octane fuels which have less energy to begin with.
    Ideally you want to increase compression (smaller volume when at maximum compression) but also increase expansion (maximum volume during power stroke.) An Atkinson engine can do this, but Atkinson engines don't idle well, and aren't suitable for a typical car. Hybrids like the Prius use Atkinson engines because they don't have to idle.
    scifes likes this.
  14. Dr_Toad It's green! Valued Senior Member

    Please back this up. That goes against all my empirical knowledge. I had a '78 Chevy 350 four-bolt (carbureted) that did quite well on 87 octane, but it just loved 115 aviation grade when I could get it. Ran clean and fierce, and I beat the mileage over the 87 by a good bit.

    I loved that truck, and folks thought it was a Harley from the throat it had..
  15. billvon Valued Senior Member

    Here's one link - http://www.appropedia.org/Energy_content_of_fuels
    From the link:
    87 octane gasoline - 125K BTU/gal
    110 octane aviation gasoline - 120K BTU/gal

    Generally hexane (a major component of gasoline) has more energy than octane. Also note that the octane RATING is not the same as the octane content; octane rating is now a preignition rating rather than a chemical term.
    Right. Higher energy does not mean higher performance in a given engine. People often make that mistake. Diesel, for example, has much more energy than gasoline - but if you mixed some in with your gasoline your engine would be very unhappy.
  16. scifes In withdrawal. Valued Senior Member

    Man that trade off web brings back memories(partially), I actually took an elective of ICEs.
    Billvon you work in the auto industry?
  17. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Did not give link as it included my Email address. Read at Bloombeg Markets Newsletter for 24/9/15.

    Not yet a smoking gun that BMW also cheated - perhaps just one out of tune car. I don't know how many of the model newspaper tested , but they did not say "an average by as much as 11%."
    Last edited: Sep 24, 2015
  18. billvon Valued Senior Member

    Not directly. I've done a lot of work for Ford and for Halo (EV charging company) though.

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